1. Field of the Invention
The present invention relates to a purge device and a purge method of performing a purge process in which an inside of a storage container, where an article is accommodated, is purged with a purge gas such as an inert gas or clean dry air.
2. Description of the Related Art
A purge device that maintains cleanliness by injecting a purge gas into the inside of a storage container, in which an article such as a semiconductor wafer or a glass substrate is accommodated, (that is, performing a so-called purge process) has been known. The purge process with such a purge device is performed in a sealed area, for example, in a purge stocker where a large amount of the purge gas is used. In order to reduce or prevent the purge gas with such a concentration that requires certain measures from discharging into the inside of this sealed area and eventually discharging from this sealed area to the outside of the sealed area, for example, as described in Japanese Patent Application Laid-Open Publication No. 2007-5604, a discharge pipe is connected to an outlet of the purge gas in the storage container and the purge gas is recovered via the discharge pipe. In the purge device with such a structure, there is not sufficient pressure to discharge the purge gas into the discharge pipe, so that the purge gas is forcibly sucked in and recovered by connecting the existing intake means or the like.
However, in the aforementioned structure, for example, if the amount of the purge gas taken in from the storage container becomes greater than the amount of the purge gas supplied to the storage container, there is a risk of rendering the pressure of the inside of the storage container negative relative to the outside of the storage container. In this case, for example, contaminated air and/or dust, or the like may be sucked in from an inlet of the purge gas or a space between a main body and a lid of the storage container, and this is not desirable.